This invention relates to a photographing number change-over device for a four lens camera having four photographing lenses with shutters and capable of simultaneously photographing four pictures on a film.
There has been a camera which is able to photograph four portraits simultaneously required for various licenses, certificates and the like, as shown in FIG. 1.
In briefly explaining, a camera body 1 includes crossed partition walls therein which divided its inner space into four equal chambers provided with photographing lenses 2 and shutters (not shown). When a release button 3 is operated, the four sets of the shutters are simultaneously opened and closed to photograph four identical pictures on an instant film 5 accommodated in a film holder 4 as shown in FIG. 2.
With such a hitherto used four lens camera, four pictures are simultaneously photographed by one photographing operation as above described. If it is desired to photograph four pictures different in expression or background one by one, it is usual to photograph four similar pictures on a film four times notwithstanding superfluity.
In order to avoid the superfluous films, it is considered to photograph only by one photographing lens with three remaining photographing lenses being covered by lens cap. In this case, the photographing is effected four times with one uncovered lens changed one by one. However, this procedure is considerably complicated and there is a tendency for the lens to be mistakenly uncapped resulting in multiple exposure. Therefore, this method involves various problems in practical use.
Moreover, there have been photographing number change-over devices for four lens cameras, for example, disclosed in Japanese Laid-open Patent Application Nos. 62-23,028 and 62-23,029 Laid-opened on Jan. 31, 1987.
The four lens camera of the former Japanese Applications is provided with conversion lenses for changing magnifications of images, while the camera of the latter is not provided with any conversion lenses. However, the photographing number change-over devices of the former and latter are quite the same in construction.
Each of the change-over devices disclosed in the above Laid-open applications includes shutters for simultaneously exposing frames of a film and shut-off devices provided in front of the film for selectively exposing at least one of the frames of the film. The shut-off device includes two screen shutters arranged one above the other and extending in tension between winding-up and winding-off drums. The screen shutters are formed with one opening, respectively, aligned with each other in a vertical direction and the other openings spaced apart from the one opening by different distances. An externally operable change-over dial is provided for driving the screen shutters. When the change-over dial is rotated in one direction, one screen shutter follows behind the other screen shutter by one section. When the dial is rotated in the reverse direction, the other screen shutter follows behind the one screen shutter. In photographing, the change-over dial is manually rotated one, two and four times for photographing four, two and one pictures.
The disclosed change-over device further includes four shut-off blades arranged two above the two other blades in front of the respective sections of the film and urged in shut-off directions, two sets of first opening means one above the other set and actuated by a change-over member to hold the shut-off blades so as to open four sections of the film, second opening means controlled by a cam member adapted to be displaced by the above change-over member and a disc rotated through 90.degree. every photographing to make operative one set of the first opening means and inoperative the other set of the means so as to alternately open two upper or lower sections and four sets of third opening means driven by the above cam member to make operative any one of the shut-off blades and inoperative the three remaining shut-off blades.
However, these change-over devices have the following disadvantages, respectively. The former change-over device needs mechanisms corresponding to two sets of focal-plane shutters one set above the other in addition to normal shutter mechanisms, so that the construction is complicated to make the camera bulky. Moreover, when photographing two or one picture, the change-over dial must be operated, so that the operations are complicated. Such complicated operations tend to be missed resulting in multiple exposure and unexposed frames of a film.
Moreover, the latter change-over device requires to have the four shut-off blades provided at every section, the first opening means for holding all the shut-off blades inoperative, the second opening means for holding the two shut-off blades operative and the remaining blades inoperative, and the third opening means for holding the one shut-off blade operative and the remaining blades inoperative. Therefore, the construction is very complicated to make it difficult to incorporate the device in a camera.